The present invention relates to a coiling method and a coiling apparatus for a metal foil, for example, in a facility of manufacturing a rolled metal foil or the like while coiling in a coiled shape and, more in particular, it relates to a coiling method and a coiling apparatus for coiling a metal foil such as stainless steel or copper with a thickness of 0.3 (mm) or less.
In a facility of manufacturing a metal foil while coiling the same in a coiled shape (for example, rolling facility), since the metal foil is coiled under tension, string elongation occurs between a deflector roll and a tension reel (coiling reel). When the string elongation portion is coiled into a coiled shape, since it is coiled in a flexed state, for example, as shown in FIG. 8, it results in crimps.
If crimps occur in the course of coiling to the tension reel, it is necessary to once stop the facility because of requirement for removing them, which lowers the productivity and results in lowering of the yield by cutting off the crimped portion. Further, in view of the productivity, it is more advantageous to manufacture a smaller number of larger unit weight coils than to manufacture a greater number of smaller unit weight coils since the load of coil handling is decreased. However, removal of the crimped portions upon occurrence of crimps also gives rise to a problem of dividing the coils thereby producing a number of smaller unit weight coils. Heretofore, in order to avoid occurrence of such crimps, it has been proposed, for example, a method of disposing an anti-crimping roll at a position just in the vicinity of a tension reel thereby preventing occurrence of crimps as described, for example, in Japanese Unexamined Patent Publication No. 63-268502 or Japanese Unexamined Patent Publication No. 1-289509. Further, it has been proposed a method of disposing a anti-crimping roll moveably and winding-up a metal foil while pressing the roll at a predetermined pressing force to the foil.
By the way, the anti-crimping roll can provide more smoothing effect as it is pressed to a metal foil at a position nearer to a contact point between the metal foil coil already coiled and a metal foil to be coiled.
However, in the method of disposing the anti-crimping roll at a predetermined position as described in Japanese Unexamined Patent Publication No. 63-268502 and Japanese Unexamined Patent Publication No. 1-289509, since the diameter of the coil increases as the metal foil is coiled, only products of small coil unit weight can be manufactured. If the coil and the anti-crimping roll are spaced apart excessively, it results in a problem incapable of completely preventing occurrence of crimps in a case of coiling an extremely thin and broad width metal foil, for example, of about 30 (xcexcm) of thickness and 1000 (mm) of width.
On the other hand, according to the method as described in Japanese Unexamined Patent Publication No. 1-245917, since the anti-crimping roll can always be controlled to an optimal position, the method is free from the problem as in the Japanese Unexamined Patent Publication No. 63-268502 and Japanese Unexamined Patent Publication No. 1-289509, but this involves a problem that determination for the pressing force of the anti-crimping roll is troublesome. That is, it involves a problem of requiring to determine an appropriate pressing force on every change of conditions such as thickness and width by conducting passage of sheets for several times, which worsens the efficiency.
In view of the above, the present invention has been accomplished taking notice on the problems not yet solved in the prior art and it is an object thereof to provide a coiling method and a coiling apparatus for a metal foil capable of easily avoiding occurrence of crimps upon coiling a metal foil in a coiled shape.
For attaining the foregoing object, the present invention provides a coiling method for a metal foil for coiling a metal foil guided by a deflector roll to a coiling reel while pressing the same by an anti-crimping roll, wherein the position of the anti-crimping roll is controlled such that the wind-up angle of the metal foil to the anti-crimping roll is greater than an aimed wind-up angle capable of preventing occurrence of crimps.
That is, since the position of the anti-crimping roll is controlled such that the wind-up angle of the metal foil to the anti-crimping roll disposed between the deflector roll and the coiling reel is a wind-up angle capable of preventing occurrence of crimps calculated based on the thickness, the width and the like, occurrence of crimps can be avoided easily.
It is preferred to control the position of the anti-crimping roll such that the wind-up angle is greater than the aimed wind-up angle and less than the aimed wind-up angle plus 20 degree. This is for preventing occurrence of undesired warps to the metal foil in view of quality.
The position of the anti-crimping roll may be controlled by automatically conducting processings of calculating the aimed wind-up angle based on the thickness and the width of the metal foil, calculating the aimed position of the anti-crimping roll at which the actual wind-up angle is greater than the aimed wind-up angle, calculating the moving amount of the anti-crimping roll from a current position to the aimed position and moving the anti-crimping roll in accordance with the moving amount. Occurrence of crimps can be prevented automatically with such procedures. Further, the aimed wind-up angle may be calculated so as to satisfy: "sgr"xxe2x88x92"sgr"m less than "sgr"c. In the equation, "sgr"x is a shearing stress exerted by a rolling tension of the metal foil to a pressed portion of the metal foil pressed by the anti-crimping roll, "sgr"m is a frictional force between the metal foil and the anti-crimping roll and "sgr"c is a buckling stress caused by a shearing stress in a plate or a cylindrical shell.
Further, the actual wind-up angle may be calculated based on a coordinate of the position for the center of rotation of the deflector roll, a coordinate of the position for the center of rotation of the anti-crimping roll and an outer diameter of the metal foil on the coiling reel.
Further, another object of the present invention is to provide a coiling apparatus for a metal foil having a anti-crimping roll for pressing the metal foil disposed between a coiling reel for coiling the metal foil and a deflector roll, wherein the apparatus comprises moving means for moving the anti-crimping roll to a predetermined position, and position control means for driving the moving means such that a wind-up angle of the metal foil to the anti-crimping roll is greater than an aimed wind-up angle capable of preventing the occurrence of crimps, and controlling a position of the anti-crimping roll.
That is, the anti-crimping roll for pressing the metal foil during passage is disposed between a coiling reel for coiling the metal foil and a deflector roll, and the anti-crimping roll is disposed movably by the moving means.
Then, the moving means is controlled by the position control means such that the actual wind-up angle of the metal foil to the anti-crimping roll is greater than the aimed wind-up angle of the metal foil to the anti-crimping roll capable of preventing occurrence of crimps that is calculated, for example, based on the thickness or the width of the metal foil, thereby controlling the position of the anti-crimping roll.
Accordingly, when an aimed wind-up angle is set in accordance with a metal foil to be wound-up, the anti-crimping roll is automatically moved to a position capable of preventing occurrence of crimps in accordance with various factors of the metal foil thereby capable of easily avoiding occurrence of crimps.
In this case, if the anti-crimping roll is moved by the moving means within a plane perpendicular to the axis of rotation of the anti-crimping roll, an actual wind-up angle of the metal foil to the anti-crimping roll can be changed easily.
Further, if the moving means comprises first moving means capable of moving within the plane in a direction of pressing the anti-crimping roll to the metal foil and second moving means capable of moving within the plane in a direction intersecting the moving trace of the anti-crimping roll moved by the first moving means, the anti-crimping roll can be moved easily within a plane perpendicular to the axis of rotation of the anti-crimping roll.